Electromagnetic device



Dec. 27, I932. o. MORGENSTERN 1,892,358

ELECTROMAGNETI C DEVI CE Filed Sept. 17, 1931 INV OR OSCAR RGENSTERN ATTORNE Patented Dec. 27, 1932 UNITED STATES PATENT OFFICE OSCAR HORGENSTERN, OF CHICAGO, ILLINOIS, ASSIG NOB TO TELE'IYPE CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE ELECTROMAGNETIC DEVICE Application filed September 17, 1881. Serial No. 563,330.

This invention relates to printin telegraph apparatus and, particularly to electromagnetic selective devices especially adapted therefor.

The present invention has for its salient object the provision of a materially simplified electroresponsive selecting device which is highly sensitive and which is capable of operating efiiciently at high speeds.

The above and other objects of the present invention are attained in an electromagnet device characterized by the use of a permanent magnet which is merely clamped to a non-magnetic support to which are adj ustably secured L shaped pole pieces constructed of thin laminations of silicon steel and contacting with the permanent magnet. Within the area bounded by the pole pieces is an electrical coil which encircles a laminated armature of relatively small cross-section ivoted beyond the coil and provided with lateral PI'O]BCi31OI1S which cooperate with the face of one leg of the pole pieces to form a path for the magnetic flux between the armature and the pole pieces when the armature is moved in response to current flowing in the electrical coil.

A more thorough understanding of the invention will be had from the following description, taken in conjunction with the accompanying drawing wherein:

Figure 1 is a lan view of a preferred form of construct on embodying the present invention illustrated in'combination with a fragmentary showing of a selector mechanism such as is used in printing telegraph apparatus. a

Figure 2 is a plan sectional view taken approximately on lines 2-2 of Figure 3.

Figure 3 is a transverse sectional elevation taken approximately on line 3-3 of Figure 1.

Figure 4 is a cross-sectional view taken approximately on lines 4-4 of Fi ures 1 and 3.

Figure 5 is a cross-sectional v1ew taken approximately on lines 5-5 of Figures 1 and 3.

In Figure 1 there is. disclosed a selector magnet construction embodying the pre' ferred form of the present invention associated witha fragmentary portion of a selector mechanism for a printing telegraph receiver, such as is disclosed with greater particularity in copending application Serial N 0. 348,612, filed March 20, 1929. Since the fragmentary showing of the selector mechanism is but illustrative of one particular application of the present invention and does not per se constitute a part of it, only so much of the mechanism is here indicated as is believed to be necessary to associate the present invention with it for its complete and'full understanding.

As is more fully described and disclosed in the aforementioned copending application, incoming telegraph signals are received over a line ware and are impressed upon a selector magnet winding 10, such as the one herein disclosed. In correspondence with the currents impressed on the winding, an armature .11 pivoted at 12'and disposed within said winding 10 is made to fluctuate into one or another of its positions as indicated in Figure 1 in solid and -in dotted outline respectively. The movement of the armature 11 subsequently results in the movement of a storage setting member, such as the cam drum 13 which, in turn, determines the setting of a plurality of selecting elements; the combined positionment of which results in the final determination and printing of a selected character.

Briefly, this is accomplished by the use of what has been referred to as a flutter lever 14 which is ivoted at 15 and which is provided with a bi urcated arm 16 having tines 17 17 The extremities of each tine 17 of the bifurcated arm 16 are turned inwardly as at 18 and straddle a radially fluted flutter cam 19. Another arm 21 extending from the pivot 15 terminates in a shouldered projection 22 which is periodically blocked in its movement by the armature member 11 as isclearly illustrated in Figure 1. A coiled tension spring 23 suitably secured to the framework of the printer engages an car 24 of the flutter lever 14, imparting a clockwise torque there- -to In the course of rotation of the flutter cam drum 13 there is normally imparted a reciprocal movement to the flutter lever 14 by the combined action of the radial flutes 25 and the tension spring 23 as is fully disclosed in the copending application, supra. This reciprocal movement is permitted or blocked in accordance with the particular positionment of extremity 26 of the armature 11 at the instant interval during which the lever 14 is urged. lVhen, during one of said intervals, the armature 11 assumes the solid line position as indicated in Figure 1 and the lever 14 is thereby blocked against its normal tendency to assume its dotted position as indicated, the continued rotation of the flutter cam 19 imparts a longitudinal shifting of the drum and flutter cam assembly. But, when during such an interval the armature assumes the dotted line position the lever 14 is permitted to pass and no such shifting occurs.

The electromagnetic structure for accomplishing the object also includes a field magnet 27 which may be of the permanent t pc or may have associated therewith a eld windin for inducing a constant magnetic flux. is apparent, the present disclosure embodies a fixed or permanent magnet 27 having associated therewith laminated pole pieces 28 of L shape which are symmetrically and oppositely disposed so as to provide an air gap 29 between their oppositely dis osed arms or projections 31. The crosshea portion 32 of the T shaped armature 11 extends between the extremities of the parallel longitudinal arms 33 of the pole pieces 28 and there are air gaps 37 and 38 between the arms 33 and the ends of the T armature 11.

As previously mentioned the armature 11 is pivoted at 12 but is limited in its reciprocal movement by the adjustment screws 34 disosed on opposite sides of its central portion.

he several laminations of the armature member 11 are rigidly held together in the preferred construction by means of suitable securing members, such as rivets 35. 1 Similan ly, the laminations of the pole pieces are also held together by rivets 36.

As is well known, the adjustment of the air gaps 29, 37 and 38 constitutes an important factor in the efiicient operation of an electromagnet since by varying the reluctance of the air gaps the flux distribution is controlled. As already described, the relative movement of the armature 11 between the oppositely disposed pole faces 39 is controlled by the adjustment screws 34. however, the adjustments of the air gaps 37 and 38 are individually controlled 'by the bodily movement of the pole pieces 28 in a longitudinal direction as permitted by the elongated screw apertures 41. Thus, it will be seen that a critical adjustment of each of the several air gaps is permitted independently of the adjustment of the remainder of said air gaps. This feature is of considerable importance in the practical operation of devices of this nature.

The magnetic force which induces the movement of the armature lever 11 is produced by the control coil 10 illustrated in the present structures as comprised of separate contiguous windings, but which may practically be comprised of a single lateral'winding. Attention is directed to the ositionment of the pivot 12 with respect to t 1e winding 10. The segregation of the pivot member from the controlling coil area, in this manner, permits of a corresponding reduction in the length of winding form 42 as well as in the pole pieces 33 and decreases correspondingly the iron losses. Spring pressure plates 43 engage shouldered portions 44 of the winding form 42 and rigidly secure the latter against vibrational effects A supporting base 45 is provided with suitable pro ections 46 adapted to be interposed between the opposite arms of the field magnet 27 and to receive thereinto clamping screws 47 for rigid securement thereby of the field magnet 27 to the supporting base 45.

Referring particularly to Figure 3, a pivot rod 48 passes transversely through the several laminations of the armature member-and is provided at its extremities with cone shaped socket bearings 49. Bearing set screws 51 and 52 support the armature lever for pivotal movement. The lower bearing screw 51 is threaded through the supporting base 45 and is locked against accidental loosening by a lock nut 53. The upper screw 52 is supported in a triangular bearing bracket 54 of non-magnetic material and is similarly locked by a lock nut 55.

The armature lever 11 includes a central lamination of somewhat heavier material extending beyond the remainder of the laminations as best indicated in Figure 3 and is suitably bent as at 56 to conform with the particular requirements of a selector mechanism such as that herein referred to. The foremost extremity of said extension is turned up as at 26 providing thereby a perendicular shouldered portion 57 for assurmg positive blocking engagement with the flutter lever 14.

It will be observed that the several parts of this device are conveniently removable for replacement purposes and that readily acces' sible modes of adjustment are provided. The permanent magnet 27 is securely clamped to the supporting base by means of the two clamping screws-47 and clamp platesv 58 m such a manner that no impairment in operating eiiiciency of the magnet itself is incurred.

In the operation of this device. as best illustrated in Figure 1, the controlling coil 10 is connected inia signaling line and a change in the direction of the current flowing through the coil will effect a change in the direction of the magnetic flux of the armature 11 and will accordingly cause its movement either individually or in series with other and similar coils. Under normal conditions; that is, with no current flowing through the winding or controlling coil 10,

thereisaconstantmagnetic flux passing across the pole pieces. However, when the coil 10 is energized by current flowing through it. a longitudinal flux is induced in the armature which is superimposed on the magnetic flux of the pole pieces. Consequently, there is a decrease in the total flux in one air gap and an increasing therein at the other gap which produces a difference in the magnetic flux and the armature in response thereto changes its position to the opposite side. When the direction of the longitudinal flux is reversed, there is a corresponding change in the other flux and the armature is restored to its previous position.

\Vhile the present invention has been disclosed and described with reference to a particular form of apparatus, it will be observed that various alternative forms and modifications may be produced without departing from the scope of the present invention. It is evident that this device is but exemplary of the present invention and it is,

therefore, intended not to limit its range to any specific structure, except as defined within the spirit of'the hereunto appended claims.

The invention claimed is:

1. In an electromagnet, a field magnet, oppositely disposed L shaped pole pieces, terminating said magnet, a T shaped armature intermediate said pole pieces and pivoted for alternative electro motive response, pole faces upon extreme ends of said pole pieces alternately effective to exert magnetic attraction upon its corresponding portion of the transversal of said armature, pole faces upon mean ends of said pole pieces adapted to exert magnetic attraction upon opposite sides of the longitudinal portion of said armature, and a controlling coil encirclin said armature and adapted to produce a ux in accordance with the current impressed thereon for either contributing to or traversing the constant flux generated by said field magnet for correspondingly positioning said armature.

2. In an electromagnet, a field magnet, a pair of pole pieces terminating the poles of said magnet and affording extreme and mean air gaps, an armature pivoted intermediate said pole pieces having a central portion d-isposed within the mean gap and a transverse portion disposed for magnetic influence at said extreme gap, a controlling coil encircling said armature adapted to receive electrical current which sets up magnetic conditions with respect to said armature to move it accordingly as said conditions are established.

3. In a selector mechanism, a selecting device including a field magnet, pole pieces for said magnet, a T shaped armature member in operative relation with said pole pieces and providing therebetween of a plurality of air gaps, and means for independently adjusting each of said air gaps without afi'ecting the adjustment of the remainder of said air gaps.

4. In a polarized electromagnet, an armature pivoted atthe junction of two halves of the alternating i'lUX, a pair of L shaped pole pieces oppositely disposed each providing a pair of pole faces to said armature, a field ma gnettor providing a onstant flux through said pole pieces, and a controlling coil encircling said armature adapted to receive electrical charges and generate alternative flux conditions for producing the movement of the armature.

5. In a selector mechanism, a selecting device including a field magnet, oppositely disposed pole pieces for said magnet, an armature intermediate said pole pieces and pivoted without the magnetic circuit of said field magnet, and-a controlling coil encircling said armature and adapted to generate alternative flux conditions in accordance with induced electrical charges for producing a movement of the armature.

6. In a selector mechanism, a controlling magnet comprising the combination of a field magnet, pole pieces for said field n'iagnet substantially of L-shape, an armature member substantially of T-shape and pivoted with respect to said pole pieces to assume alternative positions under each of which it bridges respectively opposite faces of said pole pieces, and a controlling coil encircling said armature at its intermediate limb and without the locus of its pivot whereby currents impressed upon said coil set up corresponding flux conditions and'cause movement of said armature.

I 7. In a selector mechanism, a selecting device comprising a field magnet, a pivoted armature the pivot center of which lies at one end of said armature and without the path of the alternating magnetic fiux, and a controlling coil encircling said armature for exerting a directional and controlling flux at a point upon said armature as remote from said pivot as is permitted within the confines of said field magnet.

8. In a polarized electromagnet, an armature having three vanes and pivoted at a junction thereof, and a pair of oppositely disposed pole pieces each afiording two pole surfaces one of which cooperates individually with one of said vanes and the other of which cooperates with the third of said vanes in joint opposition to the corresponding pole pieces of the other of said air.

In testimony whereof, atlix my signature.

OSCAR MORGENS'IERN. 

